UV lamp and anti-scale water treatment water heater apparatus with sanitation loop

ABSTRACT

A water heating and treatment system with UV lamp and anti-scale water treatment sanitation for suppression of pathogens including undesired bacterial content in a domestic water system includes a water heater. A cold water supply line to supply water to the water heater includes an anti-scale device, and a UV sanitation lamp. A water heater sanitation loop includes a sanitation loop pump to circulate hot water within the water heater. The water heater controller causes an activation of the water heater sanitation loop and a water temperature of the water heater to increase momentarily to a sanitization temperature above 151° F. for one or more periods of at least two minutes in a sanitation loop mode. A method for treating hot water to suppress pathogens including undesired bacterial content in a domestic water system is also described.

FIELD OF THE APPLICATION

The application relates to sanitization of water and particularly tosanitization of water in a water heater and treatment system.

BACKGROUND

Legionnaires' disease from bacteria vaporized by evaporation fromcontaminated waters contaminated with Legionella germs is a well-knownrisk. As described, for example, by the Centers for Disease Control andPrevention (CDC), in the June 2016 issue of Vitalsigns™, “Legionellagrows best in building water systems that are not well maintained.Building owners and managers should adopt newly published standards thatpromote Legionella water management programs, which are ways to reducethe risk of this germ in building water systems”.

SUMMARY

According to one aspect, a water heating and treatment system with UVlamp and anti-scale water treatment sanitation for suppression ofpathogens and undesired bacterial content in a domestic water systemincludes a water heater. A cold water supply line to supply water to thewater heater includes an anti-scale device, and a UV sanitation lamp. Asingle or multiple mixing station supplies heated water to one ormultiple temperature zones. The single or multiple mixing station isfluidly coupled to the cold water supply line and to a hot water outflowline from the water heater. The single or multiple mixing stationsupplies heated water to at least a first temperature zone at a firsthot water temperature. A water heater sanitation loop includes asanitation loop pump to circulate hot water within the water heater. Thewater heater controller causes an activation of the water heatersanitation loop and a water temperature of the water heater to increasemomentarily to a sanitization temperature above 151° F. for one or moreperiods of at least two minutes in a sanitation loop mode. The mixingstation maintains the at least first temperature zone at about the firsthot water temperature during operation of the sanitation loop mode.

In one embodiment, the water heater controller causes the activation ofthe water heater sanitation loop on a pre-determined schedule.

In another embodiment, the water heater controller is communicativelycoupled to at least one of: the UV sanitation lamp or the anti-scaledevice, and the water heater controller causes the activation of thewater heater sanitation loop in response to a detection of at least oneof: an anti-scale device failure indication or a sanitation lamp failureindication.

In yet another embodiment, the cold water supply line includes asediment filter.

In yet another embodiment, the water heating and treatment systemfurther includes a hot water recirculation line.

In yet another embodiment, the water heating and treatment systemfurther includes a one-way check valve disposed in the hot waterrecirculation line.

In yet another embodiment, the hot water recirculation line includes asediment filter.

In yet another embodiment, the hot water recirculation line includes anadditional UV lamp sanitation device.

In yet another embodiment, the hot water recirculation line includes anadditional anti-scale device.

In yet another embodiment, the water heater includes an automatic blowdown device including a blow down valve controlled by the water heatercontroller, the automatic blow down device to dispose of scale formed inthe water heater.

In yet another embodiment, the water heater includes a gas fired heaterwith a modulated burner.

In yet another embodiment, the water heater includes an indirectly firedheat exchanger.

In yet another embodiment, the indirectly fired heat exchanger isselected from the group consisting of: a plate and frame heat exchanger,a brazed plate heat exchanger, and a shell and tube heat exchanger.

In yet another embodiment, the water heater includes an indirectly firedsteam heated heat exchanger.

In yet another embodiment, the indirectly fired steam heated heatexchanger is selected from the group consisting of: a brazed plate heatexchanger, and a shell and tube heat exchanger.

In yet another embodiment, the water heater includes an electric heater.

In yet another embodiment, the water heating and treatment systemfurther includes at least one chemical injector downstream of a hotwater outlet of the water heater.

In yet another embodiment, the water heating and treatment systemincludes a hot temperature distribution water held to about a setpointtemperature by the mixing station, and a high temperature waterdistribution fluidly coupled to an outlet line of the water heaterwithout active water temperature tempering.

In yet another embodiment, the water heating and treatment systemfurther includes a one-way check valve at a hot water outlet of thewater heater.

According to another aspect, method for treating hot water to suppresspathogens and undesired bacterial content in a domestic water systemincludes: providing a water heater, a cold water supply line to supplywater to the water heater including: an anti-scale device, and a UVsanitation lamp, a single or multiple mixing station to supply heatedwater to one or multiple temperature zones, the single or multiplemixing station fluidly coupled to the cold water supply line and to ahot water outflow line from the water heater, the single or multiplemixing station to supply heated water to at least a first temperaturezone at a first hot water temperature, a water heater sanitation loopincluding a sanitation loop pump to circulate hot water within the waterheater; sanitizing a cold water before flowing or pumping the cold waterto the water heater; and sanitizing hot water of the water heater byoperating the sanitation loop pump to circulate hot water within thewater heater at an elevated temperature exceeding 151° F. (66° C.) andholding the elevated temperature in the water heater for at least 2minutes as controlled by the water heater controller.

In one embodiment, the step of sanitizing hot water of the water heaterby operating the water heater sanitation loop includes sanitizing hotwater of the water heater by operating the water heater sanitation loopon a periodic schedule.

In another embodiment, the step of sanitizing hot water of the waterheater by operating the water heater sanitation loop includes sanitizinghot water of the water heater by operating the water heater sanitationloop in response to a fault alarm of the UV sanitation lamp.

The foregoing and other aspects, features, and advantages of theapplication will become more apparent from the following description andfrom the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the application can be better understood with referenceto the drawings described below, and the claims. The drawings are notnecessarily to scale, emphasis instead generally being placed uponillustrating the principles described herein. In the drawings, likenumerals are used to indicate like parts throughout the various views.

FIG. 1 is a schematic diagram showing an exemplary UV lamp andanti-scale water treatment water heater apparatus with sanitation loopaccording to the Application;

FIG. 2 is a diagram showing recommended sanitation temperatures andtimes; and

FIG. 3 shows a drawing of an exemplary self enclosed, single cabinetimplementation of the apparatus of FIG. 1.

DETAILED DESCRIPTION

As described hereinabove, Legionnaires' disease from bacteria vaporizedby evaporation from contaminated waters contaminated with Legionellagerms is a well-known risk. Water heaters, including low volumeinstantaneous hot heater heaters, pose a significant risk if mitigationtechniques are not in place. Associated cold water supply lines and hotwater distribution systems are also at risk from contamination bypathogens such as Legionella, bacteria, and other undesirablemicroorganisms in a domestic water system.

One method to substantially eliminate Legionella and other pathogens isto heat the water to a sufficient temperature for a sufficient amount oftime. One method of the prior art is to heat water in a system to about50° C. to 60° C. for about an hour. However, such sanitation methods canalso cause several problems. Bulk heating of the water in the system forsanitation reasons uses significantly more energy consumption than mightotherwise be used. Also, the overall system or parts of the system mayneed to be removed from service during periods of elevated watertemperatures used for system sanitation cycles. More recently, it hasbeen found that further elevated water temperatures above 151° F. (66°C.) or higher can be effective in at least about two minute sanitationcycles. However, the energy cost compared normal lower hot watertemperature should still be considered.

In recent years, sanitation by ultraviolet light has become moreeffective and more widely used. One advantage of UV sanitation is thatthe UV light can be operated continuously to treat water at one or morekey point in domestic water system, such as, for example, in a coldwater supply line, and also in a recirculating water return line.

Pathogens also accumulate in scale formation at various places in adomestic water system and heater. There have been efforts related towater hardness to mitigate scale formation to prevent failure andpremature aging of various water system components. Scale buildup hasalso been found to be a gross vector for pathogens such as Legionella.Scale deposits provide a place where pathogens such as biofilms canadhere. There should also be efforts to mitigate scale formation tosubstantially prevent habitats for pathogens.

Anti-scale technologies, such as, for example, the OneFlow® anti-scalesystem, available from Watts Water Technologies, Inc. of North Andover,Mass., can be employed as part of a pathogen suppression program.Anti-scale systems are distinguished from water softening devices andsystems which are less or not effective at preventing scale buildup aspart of a pathogen suppression or mitigation program. U.S. Pat. No.9,879,120 B2, RESIN FOR PRECIPITATION OF MINERALS AND SALTS, METHODS OFMANUFACTURE AND USES THEREOF, assigned to Watts Water Technologies Inc.,describes a method of producing a scale-control resin including anaqueous solution a cation-exchange resin and a weak-acid anion mineralor salt having a multivalent cation to allow ion exchange between theresin and the multivalent cation. The cation-exchange resin may be aweak-acid ion exchange resin. The method may further include adding astrong-acid salt having the same multivalent cation as the weak-acidanion mineral or salt to the aqueous solution. U.S. Patent ApplicationSer. No. 62/675,898, QCM MEASUREMENT OF SCALE FORMATION, describes anexemplary water hardness mitigation or treatment evaluation system andmethod to evaluate the effectiveness of a water hardness mitigation ortreatment evaluation system. Such exemplary techniques can be used todevelop a fault indication for an anti-scale apparatus which can bereceived by a controller, such as the water heater controller, similarto a fault from a UV lamp device. The '120 patent and '898 applicationare incorporated herein by reference in their entirety for all purposes.

The addition of UV sanitation and/or water treatment products, such asthe OneFlow® products in a domestic water system can provide sufficienttreatment and pathogen mitigation alone. Because the energy consumptionof such systems is relatively small (e.g. the power to run one or moreUV lamps, or the power to monitor operation of a water treatment systemwhich is negligible), domestic water sanitation can be now accomplishedwithout the higher cost for the additional energy consumption used toraise the temperature of the water for sanitation by elevated watertemperature. Exemplary suitable UV sanitation systems have beendescribed in U.S. Pat. No. 9,738,547 B2, ULTRAVIOLET LIGHT SANITIZINGASSEMBLY WITH FLOW SWITCH AND KEYED LAMP, and U.S. Pat. No. 9,932,245B2, UV SANITIZING ASSEMBLIES WITH HIGH DOSE FEATURES AND METHODS FORCONTROLLING THE SAME, both assigned to Watts Water Technologies, Inc.The '547 and '245 patents are incorporated herein by reference in theirentirety for all purposes.

More advanced UV sanitation systems offer fault indications, typicallyvia a local component controller which can also be in communication witha building controller, such as, for example, a system programmable logiccontroller and/or directly in communication with the water heatercontroller (e.g. a processor or microcomputer based controller). Faults,such as, a UV lamp failure can be displayed or alarmed locally and/orthrough a building controller system. Unfortunately, it is common formany such domestic water systems to continue to provide water to endusers, including sinks and showers, sometimes for relatively longperiods of time, before a defective UV lamp or other sanitation deviceis realized to be defective and/or there can be a delay until the faileddevice is repaired. Failure of timely maintenance and repair of watersanitization components might be caused by a lack of routine system andmaintenance checks, a delay in calling for the repair, a lack of spareparts on hand, or carelessness by a building owner. After some period oftime without device repair or replacement, the domestic water system canbecome vulnerable to contamination by pathogens, as if the failedremediation equipment had never been installed.

There is a need for a water heating and treatment, system and methodwhich can effectively suppress pathogens, including undesired bacterialcontent, in a domestic water system with some degree of certainly, evenwhere one or more sanitation device has failed or is otherwiseinoperative.

It was realized that by incorporating advanced pathogen mitigationdevices as part of a water heating system, that an elevated temperaturewater heater sanitation loop can be programmatically operated onschedule, and/or operated on a fault indication from a sanitationdevice, such as a UV lamp or anti-scale device communicatively coupledto a controller of the water heater. Where the controller of the waterheater has such fault information, the controller can include a processto automatically invoke a backup or failsafe sanitation routinefollowing notification of a fault by one or more of the systemsanitation devices.

Scheduled operation of a sanitation loop: On a predetermined schedule,the controller of the water heater can command the water heater (e.g. asby modulating the burner heat output of a gas fired water heater, ascontrolled by the water heater controller) to an elevated temperaturefor a desired period of time as a scheduled backup or failsafesanitation operation.

Operation of a sanitation loop in response to a fault detection: Onnotification from one or more sanitation devices that the sanitationdevice has failed (e.g. a failed UV lamp), the controller of the waterheater can command the water heater (e.g. as by modulating the burnerheat output of a gas fired water heater, as controlled by the waterheater controller) to an elevated temperature for a desired period oftime. For example, there can be scheduled at a predetermined interval orintervals, 2 minute temperature rises of the hot water in the waterheater to above 151° F. The sanitation effectiveness of periods ofelevated hot water temperature can be enhanced by a water flow throughthe water heater, such as a water flow caused by a close-in bypass loopwhich includes a sanitation pump.

In one exemplary embodiment, the water heater includes a sanitationbypass sanitation loop with a sanitation loop pump. Either on apre-programmed schedule and/or following notice of a sanitation devicefailure from the failed device, the water heater controller runs asanitation process, where the sanitation loop is activated (includingactivation of the sanitation loop pump) and the temperature of the waterin the heater is raised by the water heater to an elevated temperaturefor an appropriate time, for that elevated temperature, to killpathogens. For example, using currently best understood sanitationtechniques, the water heater can increase the temperature in the waterheater to above 151° F. in one or periodic cycles lasting at least twominutes. Such water heater cycles can be performed by any suitablenumber of times during a day and repeated as for as long as is neededuntil the fault indication from the sanitation device goes away or isotherwise reset. As described hereinabove, there can also be sanitationcycles run on a predetermined schedule, even in the absence ofsanitation device fault indications, as a backup or failsafe mode ofoperation for a more certain pathogen suppression. An entire sanitationcycle, including heating the water to above 151° F. and at least 2minutes of relatively high water velocity (high flow rate) through thesanitation loop at the elevated temperature above 151° F.

Some hot water distribution lines may be able to continue to operatenormally without any additional manual or automatic operations duringthe times of elevated hot water temperature. For example, some hightemperature water users, such as, for example, some industrial typewashers and dishwashers can run normally even with periods of elevatedhot water temperatures such as can result from operation of thesanitation loop (where there is no mixing valve in the hot waterdistribution line). Other hot water distribution systems cannot toleratean elevated hot water supply at the sanitation temperature, such as, forexample, hot water to building sinks and showers. However, water tothose “low temperature” hot water distribution lines can be suppliedthrough a mixing system, such as, for example a digital mixing system,where cold water is automatically injected into the distribution line toensure that the desired hot water temperature, typically about 120° F.is provided, despite any short term operation of a sanitation loop atthe water heater causing higher than normal water temperature of the hotwater in the water heater as well as the hot water at the water heateroutlet line.

There can also be either a single or a multiple mixing station whichsupplies heated water to one or multiple temperature zones. The singleor multiple mixing station is fluidly coupled to the cold water supplyline and to a hot water outflow line from the water heater. The singleor multiple mixing station supplies heated water to at least a firsttemperature zone at a first hot water temperature.

FIG. 1 shows a schematic diagram of an exemplary UV lamp and anti-scalewater treatment water heater apparatus with sanitation loop 100 forsuppression of pathogens including undesired bacterial content in adomestic water system (i.e. mitigation of pathogens such as Legionellain potable water systems) according to the Application. Cold or coolwater 181 enters UV lamp and anti-scale water treatment water heaterapparatus with sanitation loop 100 from a source of potable cold water181 (e.g. a municipal domestic water utility source as distributedwithin a building) passing through a sediment filter (A) 171, anti-scalesystem 141 and UV water treatment lamp (A) 131 to ensure thatsubstantially no waterborne pathogens are introduced to the water heater110 from the municipal supply. The anti-scale system 141 is placedbefore the UV lamp 131 to substantially prevent scale formation or buildup in the UV lamp. The anti-scale system 141 also prevents scaleformation in the water heater 110. Optional booster pump 153 can providea desired water pressure and flow rate for the cold water inlet supplyline. Cold water 181 is provided to the hot water 110 (of any suitabledomestic water heater, form clarity of illustration, not shown in detailin FIG. 1) via cold water line 196, one way valve 163 (which preventshot water from the sanitation loop from flowing into the cold waterlines), and line 193 which doubles for cold water supply, and to providethe return line for the sanitation loop 101.

One suitable anti-scale system is the OneFlow® anti-scale systemavailable from Watts Water Technologies, Inc. of North Andover, Mass.Water heater 110 can be a part of a water heater device such as, forexample, any suitable water heater available from PVi™ of Fort Worth,Tex., or from AERCO International, Inc. of Blauvelt, N.Y.

Water is heated to the desired setpoint and delivered to an integralmixing valve such as a digital mixing station 160. Suitable digitalmixing stations include, for example, the IntelliStation™ available fromPOWERS™ (Watts Water Technologies, Inc.) of North Andover, Mass.Principles of mixing have been described, for example, in U.S. Pat. No.9,122,284 B2, Electromechanical temperature regulation system forproviding tempered mix water, assigned to PVI Industries Inc. (WattsWater Technologies, Inc.). Hot water from water heater 110 is providedto the mixing station 160 via one way valve 161, and hot water lines 191and 194 to provide the “first temperature” hot water 131 supply. Digitalmixing station 160 is used for tempering water to a controlledtemperature hot water supply, shown in FIG. 1 as LT supply 131. Hotwater is supplied directly to the high temperature water system, shownin FIG. 1 as HT supply 133.

Any suitable water heater 110 can be used. It is unimportant whether asource of heat, heats the water in the water heater directly (e.g. sometypes of electrical heating elements), or if there is a heat exchanger,such as, for example, where a hot combustion gas flows through tubesthat run through a water heater to heat the water. It is alsounimportant what type of fuel is used. While in commercial waterheaters, gas burning burners are common, the same system and processesdescribed by the Application can be implemented with electric, oil,direct, or indirect heat exchangers, including steam or non-potableboiler water heaters.

Exemplary suitable heat exchanger units include a plate and frame heatexchanger heater used with boiler water on one side and domestic waterheater on the other side. The higher temperature boiler water heats thedomestic water to the desired hot water temperature. Steam heating canalso be used, such as where steam runs through pipe with water flowingaround the pipe in a shell. For example, the water heater can include anindirectly fired heat exchanger, such as a plate and frame heatexchanger, a brazed plate heat exchanger, or a shell and tube heatexchanger. Or, the water heater can include an indirectly fired steamheated heat exchanger, such as a brazed plate heat exchanger, or a shelland tube heat exchanger.

Other suitable water heaters include gas fired water heaters, such asthose with a modulated burner. Electrical elements, such as, forexample, coiled electrical heating elements can also be used to moredirectly heat the water in an instantaneous type water heater. It isunderstood that water heaters as described hereinabove typically includeany suitable water heater controller (e.g. controller 201, FIG. 1).

Controller 201 is typically, but not necessarily, the same as thecontroller of the water heater 110 via communication line 203.Controller 201 is optionally communicatively coupled to UV watertreatment lamp (A) 131 via communication line 205, anti-scale system 141via communication line 209, and/or UV water treatment lamp (B) 133 viacommunication line 207. Similarly, controller 201 can be optionallycommunicatively coupled via communication line 211 to any suitablecommunication lines to peripherals, such as, for example, one or moredisplays or indicators (not shown in FIG. 1) and/or any suitable wiredor wireless connections (e.g. Bluetooth, WIFI, etc., to any othersuitable computers or controllers. Communication lines 203, 205, 207,209 and/or 211 can be any suitable wired or wireless connections of anysuitable hardwired control wires, hardwired communication bus orprotocol, any suitable wireless connection and/or any combinationthereof.

Sediment filters 171, 173 can remove undesired particulate matter beforeit enters the parts of the UV lamp and anti-scale water treatment waterheater apparatus with sanitation loop 100 at either the cold water inletor the recirculation water inlet. Any suitable sediment filter can beused.

Recirculation water is water that has gone out to a building hot waterdistribution system, but that was not used at any of the fixtures, ordevices and which can be returned via a UV lamp and anti-scale watertreatment water heater apparatus with sanitation loop 100 as “unused”hot water. In the exemplary system of FIG. 1, building recirculationwater is brought back to the UV lamp and anti-scale water treatmentwater heater apparatus with sanitation loop 100 via sediment filter (B)173 and UV water treatment lamp (B) 133, to ensure that substantially nowaterborne pathogens are introduced to the system from the building hotwater distribution lines and fixtures. Recirculated hot water 183 isdistributed directly back into the water heater via line 195 forreheating and reuse, and to the mixing valve 160 via one-way check valve165 and line 199.

Chemical injection ports 181, 183 (e.g. for chlorine dioxide) can beoptionally used to further treat the outgoing hot water from the waterheater. Chemicals such as chlorine dioxide are preferably introduceddownstream of the heat exchanger so that they do not deteriorate theheat exchanger structure.

FIG. 2 is a diagram showing recommended sanitation temperatures andtimes sanitation Loop Sequence of Operation. The Diagram shows howseveral Legionella species, including Legionella pneumophila, respond towater temperatures in a laboratory setting. In an actual hot-watersystem, legionellae may multiply at temperatures well above 122° F.because of scale, biofilm and other complexities (Legionellae Control inHealth Care Facilities: A Guide for Minimizing Risk, Matthew Freije, HCInfo, as reprinted in Understanding Potential Water Heater Scald HazardsA White Paper Developed by the ASSE International Scald Awareness TaskGroup, May 2013).

Sanitation loop—When enabled, the UV lamp and anti-scale water treatmentwater heater apparatus with sanitation loop 100 resets the setpointtemperature of the water heater from a normal operational setting (e.g.typically about 120° F. to 140° F.), up to about 160° F. As part of thesanitation or sanitation loop 101, circulating pump 151 pumps water fromthe supply connection 191 through pipe 192 to the cold inlet connection193 and continues until the water within water heater 110 temperatureexceeds above 151° F. (66° C.) and holds for at least 2 minutes, per thewater treatment recommendations of FIG. 2.

Suitable water flow rates for the sanitation loop range as caused by thesanitation pump in the sanitation bypass loop are generally at leastabout the GPM flow rate of the water heater in normal operation, orhigher. Note that a sanitation loop is distinct from bypass loops of theprior art which are used for temperature regulation and otherapplications, such as continuous water circulation or condensationreduction in the water heater. Such bypass loops use relatively smalldiameter pipes, and much lower flow rates, not suitable for the newsanitation loop described hereinabove.

Example: A water heater includes a sanitation loop as describedhereinabove using a 2″ pipe diameter and a ⅓ hp pump to achieve asanitation loop flow rate of about 80 GPM. Typically, the pump andsanitation loop pipe should be large enough to support a flow greaterthan the normal flow of heated water from the water heater (i.e. asrelated to the heat capacity of the water heater).

When complete, the setpoint can be returned to the pre-sanitation loopnormal operating temperature and the heated water will be delivered tothe mixing valve 160, and where used, to the high temperature systemwater 133 supply. The sanitation loop function can be scheduled forperiodic operation (e.g. at regular or irregular time intervals) and/oroperated based on a maintenance alarm, such as, for example, a faultindication from a water quality or water treatment device, such as a UVlamp fault or an anti-scale fault indication.

Automatic Blowdown Sequence of Operation—In some embodiments, anauto-blowdown feature can automatically drain any sediment that may havesettled to the bottom of the heater by operation of an automatic blowdown valve 121. Once complete the drain valve can be closed and the unitplaced back into its standard sequence of operation. An automaticblowdown sequence can be programmed to be performed on a regular orirregular schedule and/or on a more frequent operating schedule, suchas, for example, in response to a fault condition, such as, for example,a fault indication from the anti-scale system. Such anti-scale systemfault indications are being developed for commercialization, such as,for example, the QCM system described in the '898 application referenceto hereinabove.

Controller—the water heater can include any suitable controller,typically a processor based controller. The controller can be based onany suitable embedded processor or embedded computer. The water heatercontrol can monitor and report the status and faults of the UV fluencyand Mixing Valve, as well as perform standard water heater operationalfunctions.

The UV lamp and anti-scale water treatment water heater apparatus withsanitation loop of FIG. 1 can be built into a single enclosure as acompact self enclosed apparatus. FIG. 3 shows a drawing of an exemplaryself enclosed, single cabinet implementation of the apparatus of FIG. 1.

Applications of the UV lamp and anti-scale water treatment water heaterapparatus with sanitation loop of FIG. 1 include domestic hot waterinstallations for critical healthcare facilities such as hospitals, andin the hospitality areas, including, for example, restaurants, resorts,and hotels.

Instantaneous water heaters have relatively small volumes of heatedwater, and hot water tanks are no longer used or at least are lesscommon in modern water heating applications and installations. However,those skilled in the art will recognize that the same techniques of a UVlamp and anti-scale water treatment water heater apparatus withsanitation loop as described by the Application, can be applied to hotwater tanks of a hot water system. While present trends are towardswater heaters that heat water on demand (e.g. instantaneous waterheaters as used in the exemplary systems described hereinabove), thoseskilled in the art will also recognize that the same techniques of a UVlamp and anti-scale water treatment water heater apparatus withsanitation loop as described by the Application can also be applied totank type water heaters.

Software or firmware of processors, controllers, and computers that canbe used to implement a water heater, a digital mixing station, a UV lampand an anti-scale water treatment water heater apparatus with sanitationloop of FIG. 1 can be provided on any suitable computer readablenon-transitory storage medium. A computer readable non-transitorystorage medium as non-transitory data storage includes any data storedon any suitable media in a non-fleeting manner Such data storageincludes any suitable computer readable non-transitory storage medium,including, but not limited to hard drives, non-volatile RAM, SSDdevices, CDs, DVDs, etc.

It will be appreciated that variants of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be combined intomany other different systems or applications. Various presentlyunforeseen or unanticipated alternatives, modifications, variations, orimprovements therein may be subsequently made by those skilled in theart which are also intended to be encompassed by the following claims.

What is claimed is:
 1. A water heating and treatment system with UV lampand anti-scale water treatment sanitation for suppression of pathogensand undesired bacterial content in a domestic water system comprising: awater heater; a cold water supply line to supply water to said waterheater, said cold water supply line comprising an anti-scale device, anda UV sanitation lamp; a single or multiple temperature regulating mixingstation to supply a temperature regulated heated water to one ormultiple temperature zones, said single or multiple temperatureregulating mixing station fluidly coupled to said cold water supply lineand to a hot water outflow line from said water heater, said single ormultiple temperature regulating mixing station to supply saidtemperature regulated heated water to at least a first temperature zoneof the one or multiple temperature zones at a first hot watertemperature; a water heater sanitation loop connected to the hot wateroutflow line from said water heater including a sanitation loop pump tocirculate hot water within said water heater; wherein a water heatercontroller causes an activation of said water heater sanitation loop anda water temperature of said water heater to increase momentarily to asanitization temperature above 151° F. (66° C.) for one or more periodsof at least two minutes in a sanitation loop mode, and wherein saidsingle or multiple temperature regulating mixing station maintains saidat least first temperature zone of the one or multiple temperature zonesat said first hot water temperature during operation of said sanitationloop mode.
 2. The water heating and treatment system of claim 1, whereinsaid water heater controller causes said activation of said water heatersanitation loop on a pre-determined schedule.
 3. The water heating andtreatment system of claim 1, wherein said water heater controller iscommunicatively coupled to at least one of: said UV sanitation lamp orsaid anti-scale device, and said water heater controller causes saidactivation of said water heater sanitation loop in response to adetection of at least one of: an anti-scale device failure indication ora UV sanitation lamp failure indication.
 4. The water heating andtreatment system of claim 1, wherein said cold water supply linecomprises a sediment filter.
 5. The water heating and treatment systemof claim 1, further comprising a hot water recirculation line.
 6. Thewater heating and treatment system of claim 5, further comprising aone-way check valve disposed in said hot water recirculation line. 7.The water heating and treatment system of claim 5, wherein said hotwater recirculation line comprises a sediment filter.
 8. The waterheating and treatment system of claim 5, wherein said hot waterrecirculation line comprises an additional UV lamp sanitation device. 9.The water heating and treatment system of claim 5, wherein said hotwater recirculation line comprises an additional anti-scale device. 10.The water heating and treatment system of claim 1, wherein said waterheater comprises an automatic blow down device including a blow downvalve controlled by said water heater controller, said automatic blowdown device to dispose of scale formed in said water heater.
 11. Thewater heating and treatment system of claim 1, wherein said water heatercomprises a gas fired heater with a modulated burner.
 12. The waterheating and treatment system of claim 1, wherein said water heatercomprises an indirectly fired heat exchanger.
 13. The water heating andtreatment system of claim 12, wherein said indirectly fired heatexchanger is selected from the group consisting of: a plate and frameheat exchanger, a brazed plate heat exchanger, and a shell and tube heatexchanger.
 14. The water heating and treatment system of claim 1,wherein said water heater comprises an indirectly fired steam heatedheat exchanger.
 15. The water heating and treatment system of claim 14,wherein said indirectly fired steam heated heat exchanger is selectedfrom the group consisting of: a brazed plate heat exchanger, and a shelland tube heat exchanger.
 16. The water heating and treatment system ofclaim 1, wherein said water heater comprises an electric heater.
 17. Thewater heating and treatment system of claim 1, further comprising atleast one chemical injector downstream of a hot water outlet of saidwater heater.
 18. The water heating and treatment system of claim 1,comprising a hot temperature water distribution held to about a setpointtemperature by said single or multiple temperature regulating mixingstation, and a high temperature water distribution fluidly coupled to anoutlet line of said water heater without active water temperaturetempering.
 19. The water heating and treatment system of claim 1,further comprising a one-way check valve at a hot water outlet of saidwater heater.
 20. A method for treating hot water to suppress pathogensand undesired bacterial content in a domestic water system comprising:providing a water heater, a cold water supply line to supply water tosaid water heater, said cold water supply line comprising: an anti-scaledevice, and a UV sanitation lamp; and a single or multiple temperatureregulating mixing station to supply a temperature regulated heated waterto one or multiple temperature zones, said single or multipletemperature regulating mixing station fluidly coupled to said cold watersupply line and to a hot water outflow line from said water heater, saidsingle or multiple temperature regulating mixing station to supply saidtemperature regulated heated water to at least a first temperature zoneof the one or multiple temperature zones at a first hot watertemperature, a water heater sanitation loop connected to the hot wateroutflow line from said water heater including a sanitation loop pump tocirculate the hot water within said water heater; sanitizing a coldwater before flowing or pumping said cold water to said water heater;and sanitizing the hot water of said water heater by operating saidsanitation loop pump to circulate the hot water within said water heaterat an elevated temperature exceeding 151° F. (66° C.) and holding saidelevated temperature in said water heater for at least 2 minutes ascontrolled by a water heater controller.
 21. The method of claim 20,wherein said step of sanitizing the hot water of said water heater byoperating said water heater sanitation loop comprises sanitizing the hotwater of said water heater by operating said water heater sanitationloop on a periodic schedule.
 22. The method of claim 20, wherein saidstep of sanitizing the hot water of said water heater by operating saidwater heater sanitation loop comprises sanitizing the hot water of saidwater heater by operating said water heater sanitation loop in responseto a fault alarm of said UV sanitation lamp or said anti-scale device.